ANSWER
He started with
[tex]7[/tex]
EXPLANATION
Let the number be
[tex]x[/tex]
When Andre adds 2, the number becomes,
[tex]x + 2[/tex]
When he multiplies by 3, the number becomes,
[tex]3(x + 2)[/tex]
When 7 is subtracted, he gets,
[tex]3(x + 2) - 7[/tex]
When he adds the original number, he gets,
[tex]3(x + 2) - 7 + x [/tex]
We now equate all this to 27,
[tex]3(x + 2) - 7 + x = 27[/tex]
We expand brackets to get,
[tex]3x + 6 - 7 + x = 27[/tex]
Group like terms,
[tex]3x + x = 27 + 6 - 7[/tex]
Simplify,
[tex]4x = 28[/tex]
[tex]x = \frac{28}{4} [/tex]
[tex]x = 7[/tex]
Hence the original number is 7.
